(1. Field of the Invention)
The present invention relates generally to a readable/writable information recording medium. More specifically, the invention relates to an information recording medium for recording multimedia data containing information in different kinds of formats, including moving picture data, still picture data, and audio data; and to an apparatus and method for recording data to and replaying data from the information recording medium.
(2. Description of Related Art)
While the maximum storage capacity of rewritable optical disc media was recently 650 MB, phase-change type DVD-RAM media that are now available can store several gigabytes. DVD-RAM media are already used in the computer industry, and commercialization of the MPEG and MPEG-2 digital AV data coding standards are expected to bring new uses for DVD-RAM media in the audio-video industry.
A major area of interest is how to best use such large capacity optical discs to record image data and other AV data in ways that achieve significantly greater performance than conventional AV equipment and also offer new functionality. Furthermore, because AV equipment is not a personal computer, there are significant limitations in terms of how much memory can be provided. It is also necessary to provide an interface that is easy to use for users who are not computer literate, and that makes it possible to provide functions that are easy to understand and manipulate.
Current DVD recorders record MPEG content using a program stream format. Digital broadcasting, however, uses a transport stream format, and it is therefore preferable to directly record content using the same transport stream format. The transport stream is intended for broadcasting and communications applications, and thus does not provide for randomly accessing the transport stream. In addition, transport stream data is already digital, and can therefore be recorded without an encoding process through the DVD recorder, as is needed to record a program stream. A problem with storing a transport stream of this type to an optical disc or other medium is that random access, one of the greatest features of disc media, cannot be sufficiently achieved.
Moreover, data input using a transport stream may include data conforming to different standards and even non-standard data types. In such cases, the DVD recorder may not be able to determine the location of an intra-coded picture, or the identified address may have been recorded containing errors. A problem in this case is that when such data is replayed, data at the location of the intra-coded picture may contain errors, and normal playback may not be possible.